The Mysterious Affair at Styles is a detective novel by British writer Agatha Christie. It was written in the middle of the First World War, in 1916, and first published by John Lane in the United States in October 1920. On the morning of 18 July, the household at Styles Court wakes to the discovery that Emily Inglethorp, the elderly owner, has died. She had been poisoned with strychnine. Arthur Hastings, a soldier from the Western Front staying at this country manor as a guest on his sick leave, ventures out to the nearby village of Styles St Mary to enlist help from his friend Hercule Poirot.